Fuel injector-igniter



Jan. .14, 1964 C. H. MAY

FUEL INJECTOR-IGNITER Original Filed June 29, 1960 2 y 4 fw M E 6 4 m d l y w f 3\ E 2 a a V y T f M M m# 79 a@ d 7 J 4 a/ I Il/IIMM m w M 2 8 /0 |1|| lll AI- Y 4 B .k/ 4 0 0M In 4 I 9 2 4 4% n l 2 4 @Y United States Patent 1960. This appiication Apr. 13, 1961, Ser. No. 102,746

1 Claim. (Cl. 123-33) This invention relates generally to fuel supply systems, and more particularly to a novel fuel injector-igniter for an internal combustion engine.

This is a continuation of application Serial No. 39,693, filed lune 29, 1960, for Automotive Device, now abandoned.

Ignition of a fuel prior to or concomitantly with injection thereof into the working cylinder of an internal combustion engine has many theoretical and practical advantages, as more fully set forth in my co-pending application, Serial No. 8,784 filed February 15, 1960, now Patent 3,060,912, issued October 30, 1962.

The present invention is directed to a fuel injectorigniter for an internal combustion engine having an irnproved fuel metering system and provision for controlling the temperature of the ignited fuel charge during injection thereof into the working cylinder of the engine, thereby to deliver the ignited fuel to the working cylinder in optimum condition for continued burning and expansion.

Accordingly, one object of the present invention is an improved fuel injector-igniter.

Another object is a fuel injector-igniter having an improved fuel metering system.

Another object of the present invention is a fuel injector-igniter having provision for controlling the velocity and temperature of the ignited fuel charge.

Another object of the present invention is a fuel injector-igniter having provision for initiating a complementary shock wave to insure continued burning of the ignited fuel.

Other objects and advantages of the present invention will become apparent from a study of the following specification wherein reference is made to the drawings, in which:

FlGURE l is a sectional side elevational view of a fuel injector-igniter in accordance with an exemplary embodiment of the present invention; and

FlG. 2 is a sectional side elevation of the lower end portion A of the fuel injector-igniter of FIGURE l, enlarged for clarity.

A fuel injector-igniter 10, in accordance with an exemplary embodiment of the present invention, comprises a tubular housing 12 having an accurately finished internal bore 14 for the acceptance of a complementary plunger 16. A compression chamber 17 is dened in part by the housing 12 under the plunger 16. The plunger 16 is normally biased upwardly with respect to the housing 12 by an operating spring 18 that extends between an upper end cap 2i? on the plunger 16 and an annular shoulder 22 on the outer periphery of the housing 12. The plunger 16 is supported for reciprocable movement by and within the housing 12 to compress a charge of air to a pressure having a temperature sufficient to ignite a charge of fuel, as will be described in detail hereinafter.

3,117,564 Patented Jan. 14, 1964 ICC The plunger 16 is biased downwardly Within the housing 12 at an appropriate time in tlre operating cycle of an internal combustion engine by a suitable drive mechanism, for example, a cam shaft (not shown) that is engageable with, for example, a suitable socketed ball 23 in the end cap 20.

An annular manifold surrounds the housing 12 for the introduction of fuel and air thereinto. The manifold 30 has an air annulus 32 on the inner periphery thereof in fluid communicating relationship with a plurality of apertures 34 in the housing 12. An air intake port 36 communicates with the annulus 32. A fuel annulus is axially displaced from the air annulus 32 on the inner periphery of the manifold 30 in fluid communicating relationship with a radially outwardly extending fuel intake nipple 42. A suitable fuel conduit 44 is sealably connected to the nipple 42, as by a conventional tube fitting 46 that is threadably engaged in the nipple 42. The conduit 44 conducts fuel to the injector-igniter 10 under pressure from a suitable fuel supply source and pump (not shown).

Fuel is admitted into a nozzle assembly 50 from the fuel annulus 40 through a longitudinal passage 52 and a transverse passage 54 in a lower end 56 of the housing 12. The passage 54 communicates with a fuel inlet annulus 63 in the nozzle assembly 50, as will be described.

The nozzle assembly 50 comprises a valve plate support having an upper end face 62 that, in conjunction with a radial shoulder 64 on the housing 12, positions and supports a fuel plate stop 66. The fuel plate stop 66 has an aperture 63 therein communciating with a downwardly and angularly inwardly directed air passage '70 in the valve plate support 60. The fuel plate stop 66 also has a relatively large central aperture 72 therein to provide for communication between the air compressed within the housing 12 and a fuel plate 80. The valve plate support 60 has a threaded cenrtal bore 82 for the acceptance of a complementary valve seat 84.

The valve seat 84 has a radially outwardly extending flange 86 with a downwardly convergent upper end face 3S thereon leading into a central bore 89 for the passage of fuel downwardly through the valve seat 84. Fuel flow is accommodated by the fuel plate S0 which is movable axially of the housing 12 between the end faceSS of the valve seat 84 and the fuel plate stop 66, in a manner to be described.

A fuel inlet spring 90 of truncated conical or dished cross section is seated in a counterbore 91 in the valve plate support and has an inner upper annular edge portion 92 seated against a lower face 93 of the flange S6 on the valve seat 84, the lower outer peripheral edge thereof being normally seated in the counterbore 91.

Fuel entering the nozzle assembly 50 through the annulus 5S passes, in a manner more fully described hereinafter, radially inwardly through a passage 94 in the valve plate support 60, into anannular fuel pre-chamber 95. At an appropriate time, the fuel passes around the fuel inlet spring 90, into a fuel metering chamber 96, then radially inwardly along the underside of the fuel plate Si) and downwardly through the passage 89 in the valve seat 8d.

A tubular adapter having external threads 102 is threadably engaged in the lower end portion 56 of the housing 12. The adapter 100 has a threaded lower end portion 104 for the acceptance within, for example, a

spark plug aperture in a cylinder head of a conventional internal combustion engine (not shown). The adapter 100 has an upper end face 105 that is seated against the lower end face 106 on the valve plate support 60. A pin 107 indexes the adapter 10i) to a predetermined rotational position with respect to the valve plate support 60. A pin 168 indexes the entire nozzle assembly 50 with respect to the housing 12.

The adapter 100 has an upper central bore 109 therein for the acceptance of an upper end portion 110 of a nozzle 111. The nozzle 111 has a radial flange 112 that is seated on an end face 114 of the bore 109 to position the nozzle 111 axially of the adapter 100. A pin 115 positions the nozzle 111 with respect to the adapter 190.

A plurality of shims 116 and stacked Belleville washers 118 are seated on an upper end face 119 of the flange 112 for'the support of a nozzle plate 130. The Belleville washers 118 normally bias the nozzle plate 139 upwardly into engagement with a lower end face 132 on the valve plate support 60. The lower end face 132 of the valve plate has an annular air blast recess 134 communicating with the downwardly and inwardly extending air passage and an inner annular fuel recess 136 communicating with the passage 90 in the valve seat S4 through a plurality of vertically orientated passages 138. A central aperture 140 in the nozzle plate 130 communicates with a downwardly divergent bore 142 in the nozzle 111 for the passage of fuel, the bore 142 opening into the central cavity 144r of a diffuser cup 150.

The diffuser cup 150 has an internally threaded upper end portion 152 for the acceptance of a threaded lower end portion 154 on the nozzle 111 and is accepted in a suitable bore 156 in the lower end portion 104 of the adapter 10i).

The diffuser cup 150 has a closed lower end portion 158 that creates a shock wave, the function of which will be described hereinafter, and a plurality of intermediate transversely extending discharge ports 160 for the discharge of burning fuel into a working cylinder (not shown). A plurality of ribs 161 between the apertures 160 reinforce the lower portion 15S of the diffuser cup 150.

As a suitably timed drive mechanism for the fuel injector-igniter 10 (not shown) permits the plunger 16 to move upwardly in the housing 12 under the bias of the operating spring 18, a partial vacuum is created in the compression chamber 17 whereupon the pressure differential across the fuel plate tends to lift the fuel plate 80 from its seat on the valve seat 84 which, in turn, reduces the pressure in the fuel metering chamber 96. The reduced pressure in fuel metering chamber 96 creates a pressure differential across the fuel spring sufficient to overcome the inherent bias thereof and lift the outer diameter thereof off the valve plate support 60 to allow fuel to flow from the fuel pre-chamber to the fuel metering chamber 96. The pressure of the fuel in the fuel pre-chamber 95 which is controlled as by, for example, a needle valve (not shown) from a constant pressure source (not shown) thereafter determines the amount of fuel passing around the fuel spring 9i). By careful initial setting of the inherent bias of the fuel spring 90 and by controlling the fuel pressure in the fuel pre-chamber 95, the quantity of fuel entering fuel chamber 96 during the lill period is controlled until the pressure differential thereacross is released by the action of the plunger 16 opening the air inlet orifices 34 in the cylinder 12, whereupon the fuel spring 90 closes. The maximum quantity of fuel that may enter the fuel metering chamber 96 is defined by an uppermost position of the fuel plate 80 against the fuel plate stop 66 thereby allowing the fuel fill to relieve the pressure differential across the fuel spring 90 whereupon the fuel spring 90 closes.

When the plunger 16 uncovers the air inlet orifices 34, the compression chamber 17 fills with air, the air thereafter being compressed upon downward movement of the plunger 16 under the influence of an actuating mechanism (not shown). The increased pressure in the air chamber 17 is transmitted to the fuel plate 80 and therethrough to the fuel in the fuel metering chamber 96. Air pressure is also transmitted through air discharge orifices 68 and 7i) to the air annulus 134 and the nozzle plate 130 creating a force on the nozzle plate 13() tending to overcome the bias of the springs 118. When this force is sufficient to overcome the bias of the springs 113, the nozzle plate 131) is moved downwardly `from its seat 132 on the valve plate support 6) and both air and fuel are ejected through the central orifice of the nozzle plate 130 downwardly through the divergent bore 142 in the nozzle 110. The air and fuel are admixed, the temperature of the air being suiiicient to effect ignition of the fuel.

It has been found that the flow of the ignited air-fuel mixture through the nozzle 116 becomes supersonic tending to reduce the temperature thereof. To alleviate this condition, the diffuser cup sets up a condition for a shock wave to develop, which reduces the velocity of the air-fuel charge, thereby to preclude excessive temperature drop. This improved environment precludes extinguishment of the ignited fuel-air mixture prior to discharge of the burning fuel mixture into a working cylinder (not shown) through the ports 166 in the side of the diffuser' cup 159. The unburned portion of the fuel within the air-fuel charge finds sufficient oxygen in the working cylinder for relatively complete combustion.

The discharge of fuel through the nozzle plate 130 stops when the plunger 16 reaches its lowermost position within the cylinder 12, the air chamber 17 retaining only a negligible portion of air. The cycle is then repeated upon the withdrawal of the plunger 16 upwardly within the cylinder 12 as discussed hereinbefore.

rl`he action of the fuel plate 80 is to completely isolate the fuel and air, act as an anti-flood device, and to effect fuel metering with only a relatively small pressure differential between the chambers 95 and 96. The fuel injector 10 may be used to inject all or a part of the fuel required by the internal combustion engine (not shown) in whatever combination is found to be desirable.

From the foregoing description, it should be apparent that the fuel iniector igniter lil, in accordance with the present invention, presents a solution to the problem of ame or combustion extinguishment upon injection of a burning fuel into the working cylinder of an internal combustion engine. The novel structure and orientation thereof of the valve plate and discharge nozzle provides for relatively efficient and accurate fuel metering, and the admixing of the air and fuel charges to effect ignition of the fuel.

While it will be apparent that the embodiments of the invention herein disclosed are well calculated to fulfill the objects of the invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claim.

What is claimed is:

In combination with an internal combustion engine having a combustion chamber, a fuel injector-igniter comprising a cylinder defining an air compression charnber, a plunger at one end of said cylinder for compressing a charge of air in the chamber, a nozzle at the other end of said cylinder extending into the combustion chamber of the engine, a fuel metering chamber in said nozzle for the support of a fuel charge, a discharge valve at one end of said nozzle communicating with said fuel metering chamber, compression chamber, and the combustion chamber of the engine, said discharge valve being open able in response to a predetermined pressure differential between said compression chamber and the combustion chamber of the engine, and a diffuser cup on the opposite end of said nozzle from said discharge valve having a closed end portion aligned with said discharge valve and a plurality of transverse apertures intermediate said discharge valve and the end portion thereof whereby upon 6 the occurrence of said predetermined pressure differential, than the velocity thereof upon passage through said dissaid discharge valve is biased to the open condition and charge valve. the com ressed air and fuel charge are admixed to efect n ignition lof the fuel charge and injection thereof into the References Clted m th me of thls patent combustion chamber of the internal combustion engine, 5 UNITED STATES PATENTS the ignited fuel charge passing thruogh the transverse 865,767 Dean Sept- 10, 1907 apertures in said diffuser cup at a velocity relatively lower 1,376,277 Higgins Alm 26I 1921 1,521,807 Ford Jan. 6, 1925 

